Proteasome activity in livers of acute (100mg/kg DIC for 18h) and chronic treatment animals (10mg/kg DIC for 28 days): A, liver β1 proteasome activity; B, liver β2 proteasome activity; C, liver β5 proteasome activity. Proteasome activity in kidneys of acute and chronic treatment animals: D, kidney β1 proteasome activity; E, kidney β2 proteasome activity; F, kidney β5 proteasome activity. Data are expressed as mean ± SD (n=4), * P < 0.05, ** P < 0.001.